htlv-1 infection as a serious health issue among iranian multi-transfused patients: evidence from a systematic review and meta-analysis

background: a high prevalence of human t-cell lymphotropic virus type 1 (htlv-1) infection among general population in the northeast of iran has been reported. multi-transfused patients are known as ‘at-risk’ group for the infection. this systematic review and meta-analysis was conducted to estimate the prevalence of htlv-1 infection among iranian multi-transfused patients. materials and methods: electronic databases including pubmed, scopus, isi, google scholar, proquest, sci­encedirect, imemr, iranmedex, magiran, irandoc, isnet, ricest and sid as well as grey literatures in both english and persian were searched up to december 2013 and the related studies were critically appraised. data were analyzed with r software version 3.1.2. results: a total of 551 non-duplicate and non-overlapping citations were found in primary search, of which 18 documents surveyed htlv-1 infection prevalence among iranian multi-transfused patients. six non-duplicate and non-overlapping studies were added from grey literatures search. out of these 24 documents, 16 studies conducted among 3922 patients from 14 provinces met the inclusion criteria. the htlv-1 infection prevalence varied considerably and the highest prevalence (14.4%) was reported among hemodialysis patients from neyshabour, northeastern iran. overall estimation of htlv-1 prevalence was 3.2% (95%ci: 2.2-4.8). the htlv-1 infection prevalence among patients with thalassemia and hemodialysis were 4.1% (95%ci: 3.4-4.9) and 2.9% (95%ci: 0.96-8.3), respectively. conclusion: htlv-1 infection prevalence among patients with frequent transfusions in iran varies greatly in different parts of the country, but it is endemic in nearly all provinces. therefore, the infection should be considered as a serious health problem in the whole country. keywords: htlv-1 infections, multi-transfused patients, review, meta-analysis, iran.